Lamp construction



I May 12, 1931'.

R. A. MULLANEY LAMP CONSTRUCTION Filed March 19v. 1931- Patented May 12,1931 UNITED STATES PATENT'OFFICE RALPH A. MULLANEY, OF CHICAGO, ILLINOISLAM}? CONSTRUCTION Application filed March 19, 1931. Serial No. 524,125.

A further object of my invention is to pro vide an improved dental lighthaving means for projecting a film.

Further objects will appear from scription and claim.

In the drawings, in which my invention is illustrated.

Figure 1 is an axial section through the lamp; and v Fig. 2 is a sideelevation showing the film projecting attachment in place.

Referring to the drawings in detail, the construction shown comprises aconical casing 1, a lens 2 mounted at the front end of the easing, alamp socket 3 mounted at the rear end of the casing, a cap 4 detachablysecured to close the rear end of the casing, a reflector 5 mounted onthis cap and detachable therewith, and a film projecting attachment 6readily attachable and detachable with re spect to the lamp. A screen 7is provided in front of the lamp to prevent direct rays from the lightsource 8 from striking the eye of the person operated on and causing aglare.

The lower edge of the effective reflecting surface of the reflector liessubstantially in a horizontal plane 9, the lower portion of thereflector being rendered ineffective by means of a dead black coating10. The reflector is mounted in a suitable annular support 11 flangedover the edge of the reflector as indicated at 12 and having a flangedportion 13 secured to the cap 4. The cap may be detachably secured tothe main portion of the casing by a bayonet joint connection comprisingthe bayonet slots 1% in the cap and the bayonet pins 15 secured to thecasing.

The film projector comprises a frame or bar 16, on the front end ofwhich a condensing lens 17 is mounted and on the rear end of which afilm holder 18 is secured. The casing may be provided with a slot 19positioned and proportioned to receive the film holder so that when theframe is in position, as shown in m the de- Fig. 2, the film holder willbe properly positioned to hold a film in the path of the reflected raysA to cause an image of the film to be projected on a suitable scrcen.

As shown in Fig. 1, the light source is mounted so as to be in front ofthe focal point of rays reflected from parallel incident rays so thatthe reflected rays A from the light source converge and cross each otherat some distance in front of the lamp so that the light pattern in frontof this crossing point will be in the form of a semi-circle with aflattened upper edge. The lamp gives a very definite light pattern dueto the non-diflusing character of the reflector and the manner in whichthe reflected rays are directed and also due to the effect of the screenin front of the light source which cuts off the direct rays. 4

While I have shown and described but one embodiment of the presentinvention, it will be apparent to those skilled in the art that variousmodifications thereof may be made without departing from the spirit andscope of this invention, and, therefore, I wish to be limited only bythe prior art and the scope of the appended claim.

I cla m:

A lamp construction comprising a reflector having a reflecting surfaceof revolution and a light source in front of said reflector, the loweredge of the effective reflecting surface lying substantially in ahorizontal plane and the light source being in front of the focal pointwhereby the rays from the reflector will be convergent and the upperedge of the light pattern beyond the focal point of the reflected raysfrom the light source will be substantially horizontal, a condensinglens in front of said light source in the path of the reflected rays,said light source being below the lowermost reflected'rays whereby bulbabsorption is eliminated and an undistorted light pattern is secured,and a light screen in front of saidlight source to prevent direct raysfrom the light source from striking the condensing lens.

In witness whereof, I have hereunto subscribed my name.

RALPH A. MULLANEY.

